Fat composition and frothing oil-in-water emulsion

ABSTRACT

The objects of the present invention are to provide a whippable oil in water type emulsion, which possesses good heat resistance, excellent melting properties in mouth, freshness and cold feeling, and to provide a fat composition suitable for preparing the emulsion. A fat composition, comprising 25-60% of glycerides, of which constituent fatty acid residue has not more than 38 total carbon atoms, 25-50% of glycerides, of which constituent fatty acid residue has 42-46 total carbon atoms, and 5-25% of glycerides, of which constituent fatty acid residue has not less than 48 total carbon atoms was prepared by mixing laurin fats or hydrogenated products thereof which contain fatty acid residues with 16-24 carbon atoms or esters thereof, or a fat being rich in glycerides with fatty acid residues containing 16-24 carbon atoms, transesterifying them by a known method in the presence of a lipase having 1,3-specificity, and, if necessary, extremely hydrogenating them. Then, the fat composition obtained is used to prepare the whipping oil in water emulsion.

This application is a continuation of now abandoned application, SerialNo. 08/256,281, filed Jul. 6, 1994, now abandoned which was the NationalStage of International Application No. PCT/JP93/01620 filed Nov. 9,1993.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fat composition which has a specificcomposition, and a whippable oil in water (o/w) emulsion prepared byusing the fat composition.

2. Description of the Related Art

A large amount of laurin fats, such as coconut oil and palm kernel oil,and hydrogenated products thereof have been used in whippable creams,such as whipping cream. Cream prepared by using these fats, solely orwith natural fresh cream, has been used for cake icing and the like.Many of them have superior qualities in their physical properties tonatural fresh cream, such as excellent melting properties in mouth,freshness and cold feeling, but there are still various points to beimproved. A particular problem in a whipped cream is its poor heatresistance. Especially in summer, the whipped cream causes deformationand syneresis, when used to decorate cake or the like. Laurin fats,especially coconut oil, contains only a small amount of long-chainunsaturated fatty acids, such as oleic acid and linoleic acid.Therefore, their heat resistance are not so improved ever when extremelyhydrogenated. In addition, there is a method to give heat resistance tolaurin fats by adding a high melting point fraction of liquid oils orextremely hydrogenated oils to the laurin fats, but it is known thatthis method deteriorates melting properties of cream in mouth.

Though a trial has been performed to obtain a hardstock fat of margarineby introducing long-chain fatty acids to laurin fat (EP 0170431), notrial has been done to improve melting properties in mouth and heatresistance of a whippable cream.

SUMMARY OF THE INVENTION

The present invention provides a whippable o/w emulsion which has goodheat resistance and excellent melting properties in the mouth.

It is believed that excellent melting properties in the mouth, freshnessand cold feeling of a whippable o/w emulsion prepared by using laurinfats are derived from middle-chain fatty acids with 8-12 carbon atoms.Hence, the inventors have found that a novel fat composition can beprepared by reserving middle-chain fatty acids, which occupy more thanhalf of fatty acids especially in their 2-position as they are, andintroducing a small amount of long-chain fatty acids with 16 or morecarbon atoms to the fats, and that thereby a whippable o/w emulsion,which is imparted excellent melting properties in mouth and heatresistance, can be prepared.

That is, the present invention relates to a fat composition containing25-60% of glycerides, of which constituent fatty acid residue has notmore than 38 total carbon atoms, 25-50% of glycerides, of whichconstituent fatty acid residue has 42-46 total carbon atoms, and 5-25%of glycerides, of which constituent fatty acid residue has not less than48 total carbon atoms. And the present invention relates to a whippableo/w emulsion prepared by using the fat composition.

The fat composition of the present invention contains 25-60% ofglycerides, of which constituent fatty acid residue has not more than 38(normally 30-38) total carbon atoms, 25-50% of glycerides, of whichconstituent fatty acid residue has 42-46 total carbon atoms, and 5-25%of glycerides, of which constituent fatty acid residue has not less than48 (normally 48-56) total carbon atoms. % value indicating adistribution of number of carbon atoms in a glyceride is weight %. Thatis, the fat composition of the present invention is novel in that acontent of glycerides, of which constituent fatty acid residue has notless than 38 total carbon atoms, is less than that in laurin fats and isequal to that in milk fat, and a content of glycerides, of whichconstituent fatty acid residue has 42-46 total carbon atoms, is morethan that in laurin fats and milk fats, and that a content ofglycerides, of which constituent fatty acid residue has not less than 48total carbon atoms, is less than that in milk fats and more than that inlaurin fats. The whippable o/w emulsion prepared by using the fatcomposition has excellent melting properties in mouth, freshness, coldfeeling, and a good heat resistance. When a content of glycerides, ofwhich constituent fatty acid residue has not less than 48 total carbonatoms, are excess, a whippable o/w emulsion has good heat resistance,but has inferior melting properties in mouth. Therefore, to improve bothheat resistance and melting properties in mouth, a content ofglycerides, of which constituent fatty acid residue has 42-46 totalcarbon atoms, and glycerides, of which constituent fatty acid residuehas not less than 48 total carbon atoms, should be in the rangementioned above.

The fat composition of the present invention has following propertieswhen prepared according to a process described below: more than 40%,preferably more than 50% fatty acids at 2-position of triglycerides islauric acid, and 1,3-fatty acids are randomly distributed between thesepositions. And also, solid fat content (SFC) is 45-70% (at 20° C.) and10-45% (at 30° C.). Slipping point (in the United States, called asSofning point) is 35-45° C.

An example of preparation of the fat composition of the presentinvention is as follows: The fat composition is prepared by mixinglaurin fats or hydrogenated forms thereof with fatty acids containing16-24 carbon atoms or esters thereof, or fats rich in glycerides whichcontain fatty acid residues with 16-24 carbon atoms, transesterifyingthem by a conventional method, in the presence of lipase having1,3-specificity, and extremely hydrogenating them according to aconventional method, if needed.

As for laurin fats, it is most preferred that coconut oil orhydrogenated form thereof, wherein lauric acid is most abundant at the2-position, is used.

As for fatty acids with 16-24 carbons or esters thereof, stearic acid,palmitic acid, or ethylester or methylester thereof are exemplified. Asfor fats rich in glycerides which contain fatty acid residues with 16-24carbon atoms, vegetable oils, such as soybean oil, rape seed oil, palmoil or fractionated oils thereof are exemplified.

More definitely, when laurin fats or hydrogenated products thereof, andfatty acids or esters thereof are raw materials, it is preferred to mixat a weight ratio between 60:40 and 80:20 (laurin fats or hydrogenatedforms thereof : fatty acids or esters thereof). When laurin fats orhydrogenated products thereof, and fats rich in glycerides which containfatty acid residues with 16-24 carbon atoms are raw materials, it ispreferred to mix at weight ratio between 70:30 and 90:10 (laurin fats orhydrogenated products thereof: fats rich in glycerides with fatty acidresidues containing 16-24 carbon atoms).

As for lipases specific to 1,3-position, known ones, for example fromRhizopus, Aspergillus, Penicillium, Candida, Pseudomonas, or Mucor, canbe used. Procedures for lipases having 1,3-selectivity, lipasepreparations, or method of transesterification using them, can beperformed, according to the procedures described in, for example,JP,A,52-104506, JP,A,55-71797, JP,A,55-84397, JP,A,56-127094,JP,A,56-163196, JP,A,57-78496, JP,A,59-500649, JP,A,60-19495.

When the fat composition is prepared by random transesterification, thecomposition will contain much triglycerides, such as tristearin, whereineach constitutive fatty acid is long-chain and contains 16-24 carbonatoms.

The whippable o/w emulsion prepared by using such a fat composition willhave heat resistance, but have inferior melting properties in the mouth.When a content of triglycerides, which contain both long-chain fattyacids and middle-chain fatty acids, i.e., triglycerides consisting offatty acids with different chain lengths, is increased, “firmness” ofthe whippable o/w emulsion (crumbling to make handling difficult) willbe prevented. Hence, it is preferred that transesterification selectiveto 1,3-position is carried out.

When laurin fats rich in glycerides which contain fatty acid residueswith 16-24 carbons are raw materials, it is preferred that extremehydrogenation is carried out after transesterification of mixed fats.When separately hydrogenated fats are transesterified, elevation of thereaction temperature and use of solvents are required, which results indisadvantage in cost. Hence, it is preferred that fats are extremelyhydrogenated after transesterification.

Such fat composition obtained as mentioned above may be used to preparea whippable o/w emulsion.

In the present invention, “whippable o/w emulsion” is a creamy material,prepared by processing basic materials (the fat composition mentionedabove, proteins, sugars and water) to be an emulsion by an aid of anemulsifier. It is also called “cream for whipping”. When the whippableo/w emulsion is whipped by a foaming apparatus or a mixer for foaming,it becomes, what is called, “whipped cream” or “whip cream”.

Fat content of the foaming o/w emulsion of the present invention isnormally in a range of 20-50% based on whole emulsion.

As proteins, much proteins from non-fat solids are normally used.Non-fat solids are necessary to stabilize the emulsified state as an o/wemulsion as well as to impart milk flavor to the cream. Examples ofthese non-fat solids are skim milk powder, whole milk powder, raw cream,milk and sweetened condensed milk. Other proteins, such as casein,lactalbumin and vegetable proteins can be used. Alternatively, skim milkpowder or whole milk powder may be Maillard-treated. Such non-fat solidsare used in an amount of 1-15%, preferably 3-8% based on the totalweight.

Sugars are essential when the whippable o/w emulsion of the presentinvention is transported as fillings for breads or cakes at roomtemperature or under chilled condition. That is, to preserve the whippedmaterials for long time, decrease in water activity is required,therefore, addition of sugars is needed. Examples of sugars are glucose,maltose, sorbitol, sucrose, fructose, saccharified reduced starch,various thick malt syrups and the like. One of these sugars may be used,or more than one of them may be mixed to be use. In such cases, it ispreferred that the amount of sugars to be added is less than 50% basedon whole emulsion, calculated in an anhydrous material, and that asuitable amount of sugars is added according to the use. When more than50% of sugars are used, viscosity of the whippable o/w emulsionincreases, and various problem, such as a trouble in transportation by apump in production step, will occur.

Furthermore, emulsifiers, various salts, stabilizers and flavors, whichare used in known synthetic cream, may be co-existed in the whippableo/w emulsion. As emulsifiers, for example, a suitable amount of soybeanlecithin, sucrose fatty acid ester, polyglycerin fatty acid ester,sorbitan fatty acid ester and the like may be used. As salts, a suitableamount of alkali metal salts of phosphoric acid, alkali metal salts ofcitric acid and the like may be used. As stabilizers, a suitable amountof xanthan gum, guar gum and the like may be used.

The whippable o/w emulsion of the present invention can be preparedaccording to procedures for preparing normal field creams or imitationcreams, and can be sterilized if necessary. Homogenization or stirringcan be preformed after or before sterilization. Homogenization may bedone by either pre-homogenization or post-homogenization, otherwisecombination of both.

The whippable o/w emulsion prepared as mentioned above is suitable asfillings in breads and cakes, and can be used as nappe for a normaldecorated cakes or as cream for preparing imitation flowers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

As embodiments of the invention, the fat compositions and the whippableo/w emulsions were prepared by conventional methods according toExample 1. Furthermore, occurrence of thickened state after incubatingthe whippable o/w emulsions at 20° C. for 2 hours and stirring them,over-run after foaming them for 5 minutes using a kenwood mixer,syneresis and maintenance of shape at 20-30° C., and melting propertiesin mouth, were estimated. Results obtained from comparative experimentsare also described in Comparative Example 1 and 2.

Following examples are to be construed as merely illustrative, and notto be limitations of the spirit of the invention. In addition, parts informulation are represented by weight.

EXAMPLE 1

Eighty parts of palm oil was mixed with 20 parts of rape seed oil, andtransesterification selective to 1,3-position was preformed, thenextreme hydrogenation was carried out by a conventional method to obtaina fat composition (fat A). Composition and physical properties of fat Ais shown in Table 1. Then, according to the formulation below, awhippable o/w emulsion was prepared by using fat A. Firstly, an oilyphase was prepared by warming fat A to 70° C., and adding soybeanlecithin thereto. Separately, an aqueous phase was prepared by warmingwater at 60° C., adding sodium hexametaphosphate and sodium bicarbonatethereto to be dissolved, then dissolving or dispersing therein skim milkpowder, thick malt syrup and sorbitol in this order. Then, the oilyphase and the aqueous phase were mixed together, and sucrose fatty acidester, xanthan gum and flavor were added thereto, and the mixture wasstirred and pre-emulsified at 65-70° C. for 20 minutes using ahomomixer. Thereafter, the mixture was homogenized under a pressure ofmore than 100 kg/cm², treated by ultra high temperature sterilization(UHT) at 1400-150° C. for 4 seconds, and again homogenized under apressure of 45 kg/cm², cooled to 12° C., then subjected to aging.Estimation of the whippable o/w emulsion prepared is shown in Table 2

Formulation (%; w/w) fat A 23.6% skim milk powder 4.0% sugars (*1) 35.0%water 36.04% emulsifier (*2) 0.58% stabilizer (*3) 1.38% salts (*4)0.32% flavor 0.08% (*1) sorbitol, thick malt syrup (*2) soybeanlecithin, sucrose fatty acids ester, sorbitan fatty acid ester (*3)xanthan gum (*4) sodium hexametaphosphate, sodium bicarbonate

EXAMPLE 2

A fat composition (fat B) was prepared by mixing 70 parts ofhydrogenated palm oil with 30 parts of stearic acid, andtransesterifying selectively to 1,3-position of the glycerides.Composition and physical properties of fat B are shown in Table 1. Then,a whippable o/w emulsion was prepared according to Example 1, exceptthat fat B was used instead of fat A. Estimation of the whippable o/wemulsion prepared is shown in Table 2.

EXAMPLE 3

A fat composition (fat C) was prepared by mixing 70 parts of palm oilwith 30 parts of rape seed oil, transesterifying selectively to1,3-position, and preforming extreme hydrogenation by a conventionalmethod. Composition and physical properties of fat C are shown inTable 1. Then, a whippable o/w emulsion was prepared according toExample 1, except that fat C was used instead of fat A. Estimation ofthe whippable o/w emulsion prepared is shown in Table 2.

COMPARATIVE EXAMPLE 1

fat composition (fat D) was prepared by mixing 60 parts of coconut oilwith 40 parts of rape seed oil, transesterifying selectively to1,3-position, and performing extreme hydrogenation by a conventionalmethod. Composition and physical properties of fat D are shown inTable 1. Then, a whippable o/w emulsion was prepared according toExample 1, except that fat D was used instead of fat A. Estimation ofthe whippable o/w emulsion prepared is shown in Table 2.

COMPARATIVE EXAMPLE 2

One hundred parts of coconut oil was extremely hydrogenated to obtainfat E. Composition and physical properties of fat E are shown inTable 1. Then, a whippable o/w emulsion was prepared according toExample 1, except that fat E was used instead of fat A. Estimation ofthe whippable o/w emulsion prepared is shown in Table 2.

In reference to Table 2, the whippable o/w emulsion from Examples 1-3had good heat resistance and excellent melting properties in mouth. Thewhippable o/w emulsion from Comparative Example 1 had heat resistance asgood as from Examples 1-3, but had inferior melting properties in mouth,therefore it was intolerable as food. The whippable o/w emulsion fromComparative Example 2 had melting properties as good as from Example1-3, but had very poor heat resistance.

EFFECT OF THE INVENTION

The present invention provides a whippable o/w emulsion used in whippingcream and the like, which possesses good heat resistance as well asexcellent melting properties in the mouth, freshness and cold feeling,and provides a fat composition suitable to be applied to the emulsion.

TABLE 1 Compositions and physical properties of fat A-E distribution ofnumber of slipping carbon atoms SFC (%) point fat -38 42-46 48- 20° C.30° C. (° C.) Example 1 A 39.9 33.0 13.8 63.6 32.6 36.2 Example 2 B 34.536.6 17.3 63.4 37.7 36.0 Example 3 C 30.5 36.4 22.0 68.2 39.7 42.0Compar- D 22.5 38.5 28.5 72.0 46.0 46.0 ative Example 1 Compar- E 75.811.0  2.3 45.4  7.5 31.0 ative Example 2

TABLE 2 Estimation of the whippable o/w emulsions maintenance state ofmelting viscosity occurrence of time for of shape syneresis* propertiesfat (CPS) thickened state foaming O.R.(%) 20° C. 25° C. 30° C. 20° C.25° C. 30° C. in mouth Example 1 A 880 no  9′29″ 140 AA AA A — — —excellent Example 2 B 980 no 10′38″ 144 AA AA A — — — excellent Example3 C 850 no 12′28″ 150 AA AA A — — — excellent Comparative D 938 no14′09″ 150 AA AA A — — — inferior Example 1 Comparative E 920 no 12′15″148 A B C ± + + excellent Example 2 *maintenance of shape, state of lossof water; represent the states when imitation flowers (prepared using awhipped material) were kept at 20° C., 25° C. and 30° C. for 24 hours.maintenance of shape AA: best, without disintegration A: good, almostwithout disintegration B: with slight disintegration C: bad, withdisintegration state of syneresis +: occurred ±: slightly occurred −:not occurred

What is claimed is:
 1. A fat composition comprising an esterifiedproduct of lauric fats or hydrogenated forms thereof with (1) fattyacids containing 16-24 carbon atoms or esters thereof or (2) fats richin glycerides which contain fatty acid residues with 16-24 carbon atoms.said composition comprising: (a) 25-60% of glycerides, whose constituentfatty acid residues have not more than 38 total carbon atoms; (b) 25-50%of glycerides, whose constituent fatty acid residues have 42-46 totalcarbon atoms; and (c) 5-25% of glycerides, whose constituent fatty acidresidues have not less than 48 total carbon atoms, wherein more than 40%of the constituent fatty acid residues at the 2-position of theglycerides are lauric acid, and wherein the fat composition is preparedby mixing lauric fats or hydrogenated forms thereof with (1) fatty acidscontaining 16-24 carbon atoms or esters thereof or (2) fats rich inglycerides which contain fatty acid residues with 16-24 carbon atoms,and transesterifying them in the presence of a lipase having1,3-specificity.
 2. A fat composition according to claim 1, wherein thesolid fat content (SFC) is 45-70% at 20° C., 10-45% at 30° C., and theslipping point is 35-45° C.
 3. A whippable oil-in-water emulsioncomprising a fat composition according to claim
 1. 4. A whippableoil-in-water emulsion according to claim 3, containing 20-50% of fatsand oils and 1-15% of non-fat solid.